package com.xiyuan.almighty.service;


import lombok.extern.slf4j.Slf4j;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * @创建人 袁继鑫
 * @创建时间 2021-04-13 10:26
 * @版本 1.0
 * @描述
 */
@Slf4j
public class ReadWriteLockDemo {
    public static void main(String[] args) {
        MyCacheLock myCache = new MyCacheLock();

        int i1 = Runtime.getRuntime().availableProcessors();


        //写入
        for (int i = 1; i <= 5; i++) {
            final int temp = i;
            new Thread(() -> {
                myCache.put(temp + "", temp + "");
            }, String.valueOf(i)).start();
        }

        //读取
        for (int i = 1; i <= 5; i++) {
            final int temp = i;
            new Thread(() -> {
                myCache.get(temp + "");
            }, String.valueOf(i)).start();
        }
    }
}

class MyCacheLock {
    private volatile Map<String, Object> map = new HashMap<>();
    //读写锁：更加细粒度的控制
    private ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    private Lock lock = new ReentrantLock();

    // 存、写入的时候，只希望同时只有一个线程写
    public void put(String key, Object value) {
        try {
            readWriteLock.writeLock().lock();
            System.out.println(Thread.currentThread().getName() + "写入" + key);
            map.put(key, value);
            System.out.println(Thread.currentThread().getName() + "写入OK");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.writeLock().unlock();
        }
    }

    //取、读，所有人都可以读
    public void get(String key) {
        readWriteLock.readLock().lock();
        try {
            System.out.println(Thread.currentThread().getName() + "读取" + key);
            Object o = map.get(key);
            System.out.println(Thread.currentThread().getName() + "读取OK");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.readLock().unlock();
        }
    }

}